If it sometimes seems as if the names of dinosaurs and prehistoric animals come from another language, well, there's a simple explanation: the names of dinosaurs and prehistoric animals really do come from another language. Traditionally, paleontologists the world over use Greek to christen new species and genera — not only of dinosaurs, but also of birds, mammals, and even microbes. Partly this is a matter of convention, but partly it's rooted in common sense: classical Greek and Latin have been the shared languages of scholars and scientists for hundreds of years. (Lately, though, there has been a trend for using non-Greek roots to name dinosaurs and prehistoric animals; hence sibilant beasts like Suuwassea and Thililua.)
But enough about all that: what good does this information do you if you have to decode a mouthful of a name like Micropachycephalosaurus? The following is a list of the most common Greek words used in dinosaur names, along with their English equivalents. If you want to have some fun, try assembling your own fictional dinosaur from the ingredients below (here's a nonsense example to get you started: Tristyracocephalogallus, or the extremely rare "three-headed spiky chicken.")
Numbers
Mono = One
Di = Two
Tri = Three
Tetra = Four
Penta = Five
Body Parts
Brachio = Arm
Cephalo = Head
Cerato = Horn
Cheirus = Hand
Colepio = Knuckle
Dactyl = Finger
Derma = Skin
Don, dont = Tooth
Gnathus = Jaw
Lopho = Crest
Nychus = Claw
Ophthalmo = Eye
Ops = Face
Physis = Face
Ptero = Wing
Pteryx = Feather
Rhampho = Beak
Rhino = Nose
Rhyncho = Snout
Tholus = Dome
Trachelo = Neck
Animal Types
Anato = Duck
Avis = Bird
Cetio = Whale
Cyno = Dog
Draco = Dragon
Gallus = Chicken
Hippus = Horse
Ichthyo = Fish
Mus = Mouse
Ornitho, Ornis = Bird
Saurus = Lizard
Struthio = Ostrich
Suchus = Crocodile
Taurus = Bull
Size and Shape
Baro = Heavy
Brachy = Short
Macro = Big
Megalo = Huge
Micro = Small
Morpho = Shaped
Nano = Tiny
Nodo = Knobbed
Placo, Platy = Flat
Sphaero = Round
Titano = Giant
Pachy = Thick
Steno = Narrow
Styraco = Spiked
Behavior
Archo = Ruling
Carno = Meat-eating
Deino, Dino = Terrible
Dromeus = Runner
Gracili = Graceful
Lestes = Robber
Mimus = Mimic
Raptor = Hunter, Thief
Rex = King
Tyranno = Tyrant
Veloci = Fast
Times, Places, and Assorted Features
Antarcto = Antarctic
Archaeo = Ancient
Austro = Southern
Chasmo = Cleft
Coelo = Hollow
Crypto = Hidden
Eo = Dawn
Eu = Original, First
Hetero = Different
Hydro = Water
Lago = Lake
Mio = Miocene
Nycto = Night
Ovi = Egg
Para = Near, Almost
Pelta = Shield
Plio = Pliocene
Pro, Proto = Before
Sarco = Flesh
Stego = Roof
Thalasso = Ocean